<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0206</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2017-09-28</periodOfReport>

    <dateOfOriginalSubmission>2017-10-05</dateOfOriginalSubmission>

    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001675033</issuerCik>
        <issuerName>Great Elm Capital Corp.</issuerName>
        <issuerTradingSymbol>GECC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001715823</rptOwnerCik>
            <rptOwnerName>Kleinman Adam M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GREAT ELM CAPITAL CORP.</rptOwnerStreet1>
            <rptOwnerStreet2>800 SOUTH STREET, SUITE 230</rptOwnerStreet2>
            <rptOwnerCity>WALTHAM</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>02453</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Compliance Officer</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <footnotes></footnotes>

    <remarks>This amendment corrects the prior filing with respect to 4,072 shares of the Issuer which were previously reported in error as indirectly beneficially owned by Mr. Kleinman.  Mr. Kleinman was one of five members of the investment committee for funds managed by MAST Capital Management, LLC (&quot;MAST&quot;) that owned these shares.  However, Mr. Kleinman, in his capacity as a partner of MAST and a member of its investment committee until September 18, 2017, did not have voting and dispositive power over these shares given that investment committee decisions were made by a majority vote.  As such, Mr. Kleinman did not at any time have beneficial ownership over these shares.  Additionally, from and after September 18, 2017, Mr. Kleinman is no longer a partner of MAST or a member of its investment committee and has no involvement in MAST's investment decisions with respect to these shares.

No securities are beneficially owned.</remarks>

    <ownerSignature>
        <signatureName>/s/ Richard S. Chernicoff as Attorney-in-Fact for Reporting Person</signatureName>
        <signatureDate>2017-10-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
